Infrastructure for reading V8's initial snapshot from external files

mojo/apps/js/js_app.cc

Index: mojo/apps/js/js_app.cc
diff --git a/mojo/apps/js/js_app.cc b/mojo/apps/js/js_app.cc
index 7b400b24878c35167314fa82e7730e45166f9bba..a6f2d477f5562400c0320c95db7ec3a1360f932e 100644
--- a/mojo/apps/js/js_app.cc
+++ b/mojo/apps/js/js_app.cc
@@ -10,6 +10,10 @@
 #include "mojo/apps/js/application_delegate_impl.h"
 #include "mojo/apps/js/mojo_module.h"
 
+#ifdef V8_USE_EXTERNAL_STARTUP_DATA
+#include "gin/public/isolate_holder.h"
+#endif
+
 namespace mojo {
 namespace apps {
 
@@ -72,6 +76,10 @@ void JSApp::Run() {
   std::string file_name;
   Load(&source, &file_name);  // TODO(hansmuller): handle Load() failure.
 
+#ifdef V8_USE_EXTERNAL_STARTUP_DATA
+  gin::IsolateHolder::LoadV8Snapshot();

[rmcilroy, 2014/10/06 15:41:03]

Is this required given the change in content_handler_main.cc /
standalone_main.cc?  I think those should be enough since MojoMain should always
be called before this Run() method.

[baixo, 2014/10/07 14:53:28]

Done.

+#endif
+
   isolate_holder_.reset(new gin::IsolateHolder());
   isolate_holder_->AddRunMicrotasksObserver();